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Coal Engineering ›› 2025, Vol. 57 ›› Issue (11): 47-56.doi: 10.11799/ce202511007

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Study on control mechanisms and key parameters of surrounding rock in roadway retention by hard roof cutting

  

  • Received:2025-05-14 Revised:2025-07-11 Online:2025-11-10 Published:2026-01-09

Abstract:

To address the challenge of surrounding rock control in roadway retention under hard roofs during roof cutting, through theoretical analysis, numerical simulation, and engineering practice, a mechanical model for overburden movement in roof-cutting roadway retention and a numerical model for pressure relief roof cutting and gob-side entry retention under thick-hard direct roofs were established. The failure mechanism of surrounding rock in gob-side entries was clarified. The effects of advance pre-splitting pressure relief under different parameters were compared, the stress response characteristics of surrounding rock under varying roof-cutting parameters were analyzed, and the evolution of surrounding rock stress with working face retreat were studied. The research findings indicate: (1) The length and state of the lateral cantilever beam of the roof are key factors affecting the stability of the surrounding rock. Roof cutting actions can significantly reduce roof bending moments, with the subsidence of the roof on the gob side decreasing to 11.4% of that without roof cutting. Under thick-hard roof stratified caving conditions, the support-balanced structure can effectively control roadway deformation. The control direction of 'roof pressure relief + surrounding rock reinforcement coordination' is determined. (2) The response characteristics of surrounding rock stress to different roof cutting angles and height parameters were analyzed. The dynamic evolution characteristics of full-time vertical stress and deviatoric stress in the surrounding rock of gob-side entries under mining influence were obtained. It is clarified that the stress peaks of the solid coal rib adjacent to the retained roadway exhibit a steep-to-gentle negative correlation with both cutting angle and height. (3) A control strategy of 'roof pressure relief and high-strength anchoring; solid coal rib deep anchorage; and gob-side gangue blocking and roof support' was proposed. Field engineering applications demonstrate that under the coordinated control of roof cutting pressure relief and reinforcement support, the displacement change rate of the retained surrounding rock is low, anchor cable forces remain stable, and surrounding rock control effects are effective.

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